| // Copyright 2019 The Fuchsia Authors |
| // |
| // Use of this source code is governed by a MIT-style |
| // license that can be found in the LICENSE file or at |
| // https://opensource.org/licenses/MIT |
| |
| #include <asm.h> |
| #include <lib/code_patching.h> |
| |
| // "Unsafe" trampolines, used when speculative execution mitigations are disabled. |
| FUNCTION(__x86_indirect_thunk_unsafe_r11) |
| jmp *%r11 |
| .global __x86_indirect_thunk_unsafe_r11_end |
| __x86_indirect_thunk_unsafe_r11_end: |
| END_FUNCTION(__x86_indirect_thunk_unsafe_r11) |
| |
| // AMD-specific trampolines |
| // "Software Techniques for Managing Speculation on AMD Processors", Mitigation V2-2 |
| FUNCTION(__x86_indirect_thunk_amd_r11) |
| lfence |
| jmp *%r11 |
| .global __x86_indirect_thunk_amd_r11_end |
| __x86_indirect_thunk_amd_r11_end: |
| END_FUNCTION(__x86_indirect_thunk_amd_r11) |
| |
| // Generic x86 'retpoline' implementation |
| FUNCTION(__x86_indirect_thunk_r11) |
| call .LINT1 |
| .LINT0: |
| pause |
| lfence |
| jmp .LINT0 |
| .LINT1: |
| movq %r11, (%rsp) |
| ret |
| APPLY_CODE_PATCH_FUNC_WITH_DEFAULT(x86_retpoline_select, __x86_indirect_thunk_r11, 17) |
| END_FUNCTION(__x86_indirect_thunk_r11) |
